24 hour forecast of the surface UV for the antipsoriatic heliotherapy in Poland.

Analyses of the spectral and broad-band UV data collected at Belsk (20.79°E, 51.84°N), Poland, show that standard broad-band instrument, Solar Light (SL) 501A, could be used for measurements of both erythemal and antipsoriatic irradiance. A prognostic model is proposed for the next-day duration of outdoor exposure required to receive a dose, the so-called minimum antipsoriatic dose (MAD), equivalent to that received by standard antipsoriatic daily treatment in the phototherapy cabinet containing TL-01 fluorescent tubes. The model uses the 24 h forecast of the column amount of ozone (to predict next day clear sky UV irradiance), and low- and mid-level cloudiness (to estimate a reduction of the clear-sky UV irradiation due to clouds). The predicted duration of sunbathing required to receive a dose of 1 MAD matches the observed value, i.e. the correlation coefficients is 0.68. If the model predicts the antipsoriatic exposure over 1 MAD threshold the observed dose will be also above this threshold in 91% of cases. Thus, the model could be used for planning the next-day outdoor exposure to clear psoriasis. Hourly resolved maps, starting from 6 am up to 1 pm (GMT), showing the duration of antipsoriatic exposure over Poland are made public. The model provides a tool for a psoriatic patient to find the sunbathing starting time and its duration, which has the same healing potential as a single indoor phototherapy session.

Perspectives of the antipsoriatic heliotherapy in Poland.

Statistical analysis of the daily course of exposures to TL-01 tube radiation for 93 psoriatic patients from the Medical University of Lódz during 20-day phototherapy shows that the dose of 1 J/cm(2) represents a unit of single exposure necessary for psoriasis healing. This value is converted to the antipsoriatic effective dose of 317.9 J/m(2) using the TL-01 lamp irradiance spectrum and the antipsoriatic action spectrum. It is proposed that the daily exposure of 317.9 J/m(2) serves as the standard antipsoriatic dose (SAPD) providing a link between the cabinet and the out-door exposures and it could be used for planning heliotherapy in Poland. A model is proposed to calculate ambient antipsoriatic doses for 3 h exposures around the local noon (9 am-12 am GMT) based on satellite measurements of ozone and cloud characteristics. The model constants are determined by a comparison with pertaining antipsoriatic doses measured by the Brewer spectrophotometer in central Poland. It is found that 3 h exposures to solar radiation in the period 15 May-15 September provides the mean (2005-2013) doses in the range 2.7-3.1 SAPD over Poland. Thus, heliotherapy could be treated as an alternative to the cabinet phototherapy for almost 4 months. It seems that the most effective site for antipsoriatic heliotherapy is the south/east part of Poland (the Bieszczady Mountains). The heliotherapy could be carried out in existing national health centers equipped with the standard easy-to-use biometers for on-line monitoring of UV level and controlling duration of sunbathing to avoid erythema risks. It is even possible to control the antipsoriatic heliotherapy by a patient himself, using low-cost hand-held instruments measuring UV index.

Space-based estimation of the solar UV-B doses for psoriasis heliotherapy in Poland using OMI data for the period 2005-2011.

A UV model is proposed to reconstruct the biologically weighted doses at the ground-level, erythemal, vitamin D(3), and antipsoriatic effective doses, based on the space data from the Ozone Monitoring Instrument on board of NASA EOS Aura spacecraft for the period 2005-2011. The model is training using the results of spectral UV measurements carried out at Belsk, Poland. The model outcome is verified using the UV spectra measured at Hradec Kralove, Czech Republic. The model uncertainty is almost the same for all examined action spectra and comparable to that found in earlier studies on differences between the satellite overpasses and ground-based erythemal data. Antipsoriatic doses, taken during 2h exposure periods near local noon, are reconstructed for selected sites in Poland to find if heliotherapy would be an alternative to standard treatment of psoriasis by tube irradiation in medical cabinets. Mountain-resort in the southern Poland, Zakopane, and rural-site in Central Poland, Belsk, are among the best location of potential heliotherapy centers in Poland for late spring/summer season. Leba, resort on the Baltic Sea coast, is a potential heliotherapy center in June and July. The methodology to disclose possible heliotherapy periods over the territory of Poland could be extended to any region. It would help to prepare an optimal schedule of antipsoriatic heliotherapy that accounts for local weather conditions and medical standards of using UV cabinets.

Effectiveness of heliotherapy for psoriasis clearance in low and mid-latitudinal regions: a theoretical approach.

The action spectrum for psoriasis clearance is reconstructed taking into account the results obtained in the early 1980s. The antipsoriatic action spectrum is used for weighting the medical cabinet UV spectra, and the solar spectra measured in San Diego (USA) and Belsk (Poland). The mean cumulative antipsoriatic effective dose of 450 mJ cm(-2), due to TL-01 (UVB narrowband) tubes, is taken by a patient with skin phototype II during routine 20 phototherapy sessions carried out in a phototherapy cabinet in the Medical University of Lódz. Thus, the daily mean dose of value 22.5 mJ cm(-2) is proposed as the threshold for daily solar dose for numbers of out-door exposures to clear psoriasis. We assume that the heliotherapy will last a whole month with every day 2h exposition to the direct sunlight around local noon. The heliotherapy will be successful if weather conditions permit at least 20 days with the daily exposure over the threshold. The minimum cumulative ambient erythemal dose, necessary for psoriasis clearance, is estimated as 144 standard erythema dose (SED) for the whole heliotherapy period. We find that heliotherapy could be effectively used in March through October (San Diego) and in June through August (Belsk). Thus, the heliotherapy against psoriasis is possible not only at southern resorts but even at the mid-latitude sites.

A mathematical model for seasonal variability of vitamin D due to solar radiation.

It is widely recognized that vitamin D deficiency has detrimental health consequences. The ultraviolet (UV) B radiation increases the serum vitamin D level, expressed by 25-hydroxyvitamin-D(3) [25(OH)D]. An analytical model is presented to calculate the serum 25(OH)D changes throughout a year, caused by the solar exposure variability due to geophysical and habitual factors. The model is tuned by taking into account recent experimental results of serum 25(OH)D changes, after a series of artificial (by fluorescent tubes) UV exposures. The model uses the erythemal and vitamin D weighted irradiances, inferred from the Brewer spectrophotometer and the Kipp and Zonen broad-band meter measurements, carried out in Belsk (52°N, 21°E), Poland, in 2010. The modeled seasonal pattern of the serum 25(OH)D concentration in Polish indoor workers is only slightly different, than in subjects with typical outdoor activity habits, and in those with sun-seeking behavior. A deep minimum in the serum 25(OH)D concentration appears in late winter, regardless of outdoor activity habits. An extra sunbathing to boost the vitamin D level is not worth taking, because of a minor improvement of the vitamin D status, and because of a greater erythema risk. It would be much safer and more effective to maintain an adequate vitamin D level through diet supplements, even in summer, for non sun-seeking subjects.